1. Field of the Invention
This invention relates to thin laminate film structures for electrostatic or magnetic applications and methods for making such thin laminate film structures.
2. Description of the Related Art
One type of electrostatically actuated device with which the thin laminate film structures of this invention may be used is a flexible film, such as a flap or a diaphragm, of a fluid valve. For example, fluid valves having cantilevered blocking films are disclosed in U.S. Pat. No. 6,032,923 to Biegelsen et al., which is incorporated herein by reference in its entirety.
As shown in FIG. 1, a valve 90 has a valve housing 92 that defines an inlet port 94 and an outlet aperture 96. The valve housing 92 is formed by an aperture plate 98 and an opposing port plate 100 positioned in a spaced apart relationship to the aperture plate 98. The aperture plate 98 and the port plate 100 may be separately formed as distinct layers and bonded together with an adhesive layer 99. The port plate 100 may have a curved surface 101 as shown, or may be flat. The aperture 96 is laterally offset from a flap comprising a flexible film 102.
The flexible film 102 is sandwiched between the aperture plate 98 and the port plate 100. The flexible film 102 may have a fixed end 103 held in position between the plates 98 and 100, and an unfixed end 104 that is free to move between the plates 98 and 100. The flexible film 102 is at least in part conductive so that a voltage can be applied to reliably switch the flexible film 102 between an aperture blocking position in which the inlet port 94 is blocked and an aperture open position in which the inlet port 94 is unblocked.
An electrode 106 connected to an electrode voltage source 107 is disposed in the port plate 100. A dielectric layer 97 may be formed on the port plate 100, as shown, or may be incorporated as part of the flexible film 102. When the valve 90 is part of an addressable array, a film voltage source 105 is connected to the fixed end 103 of the flexible film 102. Application of a voltage between the electrode 106 and the flexible film 102 generates an attractive electrostatic force between the electrode 106 and the flexible film 102 to cause the flexible film 102 to move into the aperture blocking position in which the inlet port 94 is blocked.
Other examples provide fluid valves having a diaphragm or membrane as a blocking film, such as the electromagnetic valves disclosed in U.S. Pat. No. 6,123,316 to Biegelsen et al., which is incorporated herein by reference in its entirety.
As shown in FIG. 2, an electromagnetic valve 200 is formed by laminates 202 that define a chamber 203 with an inlet conduit 225 and an outlet conduit 226. A compressively stressed diaphragm 210 made of substantially uniform permalloy or other magnetically susceptible material is positioned in the chamber 203. The diaphragm 210 is stressed to normally close the valve 200 by blocking the outlet conduit 226.
An electrical lead such as a copper planar coil 216 is formed on a dielectric layer 218 of a permalloy layer 214. A certain voltage applied to the coil 216 generates a current which generates a magnetic field providing a sufficiently attractive electromagnetic force between the coil 216 and the diaphragm 210 to pull diaphragm 210 into a non-blocking position 220 to open the valve 200. Reducing or removing the applied voltage allows the diaphragm 210 to spring back into its normal position due to its mechanical bias, and close the valve 200 by blocking the outlet conduit 226.
This invention provides a thin laminate film structure that allows separate determination and/or optimization of mechanical and electrical or magnetic properties.
This invention separately provides a thin laminate film structure that allows efficient actuation of electrostatically and/or magnetically driven devices.
This invention separately provides a thin laminate film structure that allows a lower voltage to be applied to generate an electrostatic or magnetic force that is sufficient to move the film structure.
This invention separately provides a thin laminate film structure that has stiffness optimized for a given electrostatic or magnetic application.
This invention separately provides a thin laminate film structure that has a desired strength for a given electrostatic or magnetic application.
This invention separately provides a thin laminate film structure for an electrostatically or magnetically actuated valve device.
This invention separately provides a thin laminate film structure that allows dual-direction actuation of electrostatically and/or magnetically driven devices.
This invention separately provides methods for making a thin laminate film structure.
In various exemplary embodiments of the thin laminate film structure and methods according to this invention, a metallic lamina is formed on a surface of a dielectric lamina and a third lamina is formed on a surface of the metallic lamina opposite the dielectric lamina. In various exemplary embodiments, the third lamina is attached to the metallic lamina by a thin film adhesive. In other various exemplary embodiments, the third lamina is attached to the metallic lamina by a thermal compression bond.
In various exemplary embodiments of the thin laminate film structure and methods according to this invention, the metallic lamina comprises a first metallic lamina. A second metallic lamina is formed on a surface of the third lamina opposite the first metallic lamina. A second dielectric lamina is formed on a surface of the second metallic lamina opposite the third lamina.
These and other features and advantages of this invention are described in, or are apparent from, the following detailed description of various exemplary embodiments of the systems and methods according to this invention.